1. Field of the Invention
The present invention, in at least certain embodiments, is directed to heat pump systems with enhanced efficiency that control inlet water supply temperature by the inclusion steam turbine(s) and/or fuel cells in a water circuit; and to power generation systems that use waste heat exchange system to dissipate heat from air conditioning systems that employ earth loop heat exchange apparatus.
2. Description of Related Art
The prior art discloses a variety of air conditioning systems that provide cool air and exhaust hot air. In many such systems the hot air generated by an air conditioner is vented to the atmosphere. The prior art also discloses a wide variety of earth heat exchange systems which typically include conduit, conduits, and/or a pipe loop within the earth, apparatus for circulating heat transfer fluid therethrough and through other systems or apparatuses above the surface. When such an earth heat exchange system is used with an air conditioner, e.g., but not limited to a heat pump, the heat that must be dissipated in the earth can overload or overwhelm the system and/or slow down the cooling process.
There has long been a need, recognized by the present inventor, for an air conditioning system that can efficiently and effectively use an earth loop heat exchanger. There has long been a need, recognized by the present inventor, to usefully employ the waste heat generated by such a system.
The present invention, in at least certain embodiments, discloses HVAC (heating, ventilation, and air conditioning) systems that increase the efficiency of heat pumps and fuel cells by lowering or raising temperature of water supplied to a heap pump. The temperature of the supply water, in certain aspects, is controlled by the operation of a device, e.g. a water/refrigerant/water heat exchanger. In one aspect, excess heat rejected by the heat pump(s) and/or fuel cell(s) to the water loop system is used by a steam turbine to produce electric power.
The present invention, in at least certain aspects, discloses a system for providing relatively cooler input water to air conditioning apparatus and/or heat pumps operating in a cooling mode and, in certain aspects, the use of rejected heat from the air conditioning apparatus and/or heat pumps to generate electricity and to facilitate the production of electrical power. In one aspect, earth heat transfer loops facilitate the provision of relatively cooler input water for the air conditioning apparatus and/or heat pumps.
The present invention, in certain aspects, discloses a system for using waste heat generated by an air conditioning system that utilizes one or more earth loop heat exchangers or other thermal buffer. In one embodiment, the present invention provides a system that includes one or more heat pumps used to produce cool air for cooling a building or other structure. Heat from the one or more heat pumps is supplied to a mechanical heat exchanger, e.g., but not limited to, a water-to-refrigerant-to-water device, which extracts heat from the fluid. Water superheated by this heat exchanger is converted to steam to power a turbine that rotates a generator to produce electricity. Optionally, material to be vented from the steam turbine is fed to a vent heat exchanger to recover useful heat from the material prior to venting it. As needed, supply or xe2x80x9cmake-upxe2x80x9d water is provided from a water supply to the system and to replenish a steam production circuit. Such water is, optionally, pure, distilled and/or filtered with appropriate filtration apparatus, e.g. to remove foreign materials or undesirable substances or compounds which could foul a heat exchanger or inhibit the heat transfer process.
In certain embodiments, a closed loop water circulation system thermally connects the heat pump water system to heat removal equipment (i.e. water to refrigerant to water heat exchanger) and to the heat storage device or xe2x80x9cthermal bufferxe2x80x9d (i.e. pipe loops installed in the earth, ice storage, lake, water tank, etc.), to the optional waste heat production equipment (i.e. fuel cell), and to a steam-turbine-powered electric generator.
In one aspect, by using a power generating apparatus and heat pump(s) according to the present invention, the size of an earth loop heat exchange system (or other thermal buffer) can be reduced since the amount of heat from the heat pump(s) that must be dissipated in the earth via earth loops of the system is reduced. The heat used to generate power can be, but does not need to be, dissipated in the earth. Consequently a smaller field of multiple earth loops can be used in such a system.
In one aspect, by including a water-to-refrigerant-to-water heat extracting device into a heat pump water circuit according to the present invention, more heat can be removed from the heat pump water circuit than can be removed by direct conductive heat transfer. For example, if the temperature of the earth is 70 degrees F., the returning water temperatures to the heat pumps will not be below 70 degrees F.; and as heat is transferred to the earth as the heat pumps operate in the cooling mode, earth temperatures increase resulting in higher and higher temperature water being returned to the heat pumps. The supply water to the heat pumps can be reduced below the temperatures possible in a conventional closed or open loop xe2x80x9cgeothermalxe2x80x9d heat pump system. This relatively cooler inlet water results in much higher operating efficiencies of the heat pumps when they are operated in the cooling mode, and in one particular aspect reducing the electric power required by the heat pump by about 50%. By using the heat rejected by the system to economically produce valuable electric power, the cost of extracting this waste heat is more than offset.
In another aspect, in a system according to the present invention, when a device such as a fuel cell is connected to the supply/return water system, some (or all) of the waste heat generated by the fuel cell, instead of being used to generate power, is diverted to increase the inlet water temperature to the heat pumps when they are operating in a heating mode. Similarly, the heat pumps can be fed water at much higher temperatures than is possible in a conventional geothermal heat pump system, again resulting in much higher operating efficiencies. Also, it is within the scope of the present invention to exhaust some or all of the heat produced by a fuel cell to the atmosphere. Water produced by fuel cell(s) can be used in the system.
In yet another aspect in a system according to the present invention, a heat pump or pumps are operated in the heating mode and a fuel cell (or fuel cells) is connected to the system; thus an earth loop heat exchanger in the system is reduced in size since less heat is required from the earth due to the heat extracted from the fuel cell(s). The use of smaller earth heat exchangers and/or thermal buffer(s) can result in capital savings in construction.
What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain preferred embodiments of the invention, other objects and purposes will be readily apparent to one of skill in this art who has the benefit of this invention""s teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, nonobvious systems for increasing the efficiency of an air conditioning system that uses an earth loop, lake loop, ice storage, or buffer storage tank heat exchange system; and methods for dissipating the waste heat generated by an air conditioning system that uses an earth loop heat exchange system and/or thermal buffer(s);
Such systems and methods that utilize excess produced heat and/or waste heat to generate power;
Such systems and methods with relatively smaller earth loop systems and/or systems with fewer earth loops, or systems with more earth loops based on the amount of heat used to generate power, heat that does not have to be dissipated in the earth;
Such systems and methods with relatively smaller heat buffer and/or storage systems; and systems with more earth loops based on the amount of heat required to economically generate power; and
New, useful, unique, efficient, nonobvious devices, systems, and methods for producing power using an air conditioning system that employs an earth loop heat exchange system.
Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures and functions. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention.
The present invention recognizes and addresses the previously-mentioned problems and long-felt needs and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one skilled in this art who has the benefits of this invention""s realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent""s object to claim this invention no matter how others may later disguise it by variations in form or additions of further improvements.